SPECTRA is an application software to calculate optical properties of synchrotron radiation (SR) emitted from bending magnets, wigglers (conventional and elliptical) and undulators (conventional, helical, elliptical and figure-8). Calculations of radiation from an arbitrary magnetic field distribution are also available. Parameters on the electron beam and the source can be edited completely on graphical user interfaces (GUIs) and it is possible to show the calculation result graphically. The energy spectrum and radiation power after transmitting various filters and convolution of detector's resolution are also available.
Important Notes for Mac OS X 10.12 (Sierra) Users
Because of the security enhancement made in this OS, many (freely-available) applications downloaded from anywhere out of the App Store may fail, which is known as an "App Translocation" problem. To avoid this and run SPECTRA correctly, the users should once move the executable file ("spectra" application file in the SPECTRA directory, or more correctly "spectra.app" directory) to somewhere out of the SPECTRA directory, then return it to the original location. This "incantation" will fix the problem.
If the users are presenting or publishing their results obtained with using SPECTRA, they are kindly requested to cite the related reference(s).
The graphical part of SPECTRA is written in the C++ language with wxWidgets GUI tool kit and OpenGL graphic library. Thanks to portability of these libraries, SPECTRA will run on most available operating systems such as Microsoft Windows, Mac OS X, Linux, and most unix-like operating systems.
Important Notes on Brilliance Calculation
In version 10.0, rigorous estimation of brilliance based on the Wigner function method has become available, which is in contrast to the traditional method based on the Gaussian approximation. Although the brilliance estimation by the Gaussian approximation is still available for compatibility with the older versions, it is referred to as GA.Brilliance (Gaussian-Approximated) and is distinguished from the rigorous estimation.
Energy spectra of the brilliance, flux density, partial flux after passing through a slit, and total flux
Spatial dependence of the flux and power densities
Beam size, angular divergence, coherent flux as a function of the gap and K value
The peak brilliance, flux, and radiation power as a function of the gap and K value
Radiation power after passing through a filter composed of various material
Far-field approximation for fast evaluation of radiation
More precise estimation of radiation in the near-field zone
Rigorous brilliance evaluation of SR based on Wigner function representation
Coherent mode decomposition of partially coherent SR
GUI for Pre and Postprocessor
SPECTRA is equipped with a full graphical user interface to help the user to input and edit parameters necessary for SR calculation, and to visualize the results of calculation. Examples of the preprocessors are shown below.